Particularly at Puente (Figure 4(A), Figure 4(B)), the deposit’s depth varied according to its location in the site, and each stratum is labeled with Roman numerals I to XIV (Figure 4(C)). The analyzed material comes from strata XIIA to XIV, located in the front part of the rock shelter talus and indicated with colors in Figure 4(C). XIIA is ~8 cm thick and formed of yellowish-brown sediment. Covering a surface of ~87 square meters, layer XIII is light brown sediment with yellowish spots ~15 cm thick. Finally, XIV is the deepest stratum, deposited over the bedrock. It is composed of light-yellow sediments mixed with volcanic ash. Archaeological finds primarily come from layers XIIA-XIII, while XIV yields the smallest numbers from grids S4, S5, S4E1, S6E1, and S7E1.

Figure 4. (A) General view of Puente site from the Wichqana creek. (B) Puente site floor plan of excavations. (C) Detailed stratigraphic sequence recorded in the east-west section of the Puente rock shelter (Figure 3(B), Figure 3(C), Redrawn from García Cook and [72]: p. 81, fig. 4-1, 4-10, 88-89).

Analysis

The analyzed sample (n = 4052) from El Puente, spanning levels XIIA to XIV (XIV: n = 38, XIII: n = 1810, XIIA: n = 2204), is detailed by typological list, raw materials, and average measurements in [138]. Unifacial tools are primarily end-scrapers (Figure 5(U), Figure 5(X), Figure 5(Y), Figure 5(C’)) and marginally retouched flakes (Figure 5(W), Figure 5(B’)), with fewer side-scrapers and denticulates (Figure 5(V), Figure 5(Z), Figure 5(A’)). Records indicate unifaces were mainly crafted from tertiary flake blanks (Figures 5(U)-(Z), Figures 5(A’)-(C’)) with some use of primary and secondary flakes (Figure 5(D’)). Retouch was predominantly direct (Figures 5(U)-(D’)), with inverse retouch occurring less frequently. Rhomboidal points, along with three complete lanceolate, bi-pointed examples with impact-fractured tips and bases (Figures 5(A)-(P)), originate from levels XIIA-XIII. Some points retain evidence of the flake blank due to short retouch (Figure 5(D)-(H)). Bifacial implements, typically exhibiting resharpening and reworking (e.g., [2], [16]; [94]), show significant rejuvenation in specimens displayed in (Figures 5(I)-(K), Figure 5(M), and Figure 5(P)), a pattern observed in other Peruvian sites (e.g., [61]: fig. 2a-h; [120]: fig. 44k-l and n-o). Additionally, five bifacial pieces from layer XIII were discarded due to flaking errors like hinges, steps, and oblique fractures (Figures 5(Q)-(T); [18]). It is important to note that the majority of the sample consisted of sedimentary rocks, primarily sandstones and calcareous materials; however, igneous rocks were predominant in layers XIIA to XIV ([138]: figures 9 and 11). These rocks can be found in the ravines of a seasonal creek located approximately 50 meters from the site, which serves as a secondary source ([56]). The creek contains pebbles of quartzite, basalt, granodiorite, rhyolite, and volcanic tuff. Additionally, various types of flint-like materials and cherts, derived from unknown sources, were identified. Concerning obsidian, four samples from layers XII-XIII were analyzed using XRF and NAA methods. The analysis revealed that two artifacts originated from the known sources Quispisisa and two from Puzolana ([13]: table 12; [14]: pp. 293-293). From layer XIII, the manuports and ecofacts included a hammerstone and pebbles obtained from the nearby Wichqana Creek. The shapes of these pebbles varied, ranging from circular to elliptical and oblong. The hammerstone shows percussion marks on one of its sharp sides, while one of the pebbles has traces of soot, likely indicating some combustion activity.

Twenty-six bone remains were identified from the analyzed strata, of which six were modified by grinding and polishing, and twenty were altered by fire. Two well-made awls from XIIA are shown in Figure 6(A), Figure 6(B), previously reported as “Split and Conical awls” and a “Polished bone fragment and Tubular bone bead” (Figure 6(G), Figure 6(L). From layer XIII come ten burned specimens; seven are well-crafted objects, while the remainder are small bone fragments (Figure 6(F), Figure 6(H), Figure 6(J), Figure 6(K)). Remarkable pieces were classified as “Pierced base netting needles” (Figure 6(I)) and “Triangular Pendants” (Figures 6(C)-(E)) ([75]: fig. 7-12, 8-14). The latter were achieved by grinding on some abrasive material that left striae visible to the naked eye; finally, polishing was employed to finish them. The materials are promising and show the skill of the pre-Hispanic settler in making beads with the remains of fauna. We continue to record other bone artifacts from the following level XII (Figure 6(M)), which will be addressed in another report.

Figure 5.Projectile points in different conditions recovered in stratum XIII (A)-(O) and XIIA (P) of the Puente site. Bifacial stages of manufacture from layer XIII (Q)-(T). Examples of unifacial tools from layer XIIA (U)-(D’). The arrows in this figure point to the close-up pictures of the edges depicted on the right of each specimen.

Figure 6.Bone specimens from level XIII in Puente: Triangular pendants (C)-(E), unclassified fragment ((F), (H), (J), (K)), pierced base netting needles (I); XIIA:Conical bone awls (A), Split bone awl (B), Polished bone fragment (G), Tubular bone bead (L); XII: Tubular bone bead (M).

The Jaywamachay rockshelter (13˚18'55.96''S, 74˚21'15.60''W, 3350 m.a.s.l) is located on the lower side of a rocky mountain, 200 m from the Cachi river bridge. It is situated on the side of the mountain, where a concavity was formed that is ~27 m wide and an average of 5 m deep (Figure 7(A)), covering a surface of ~72 square meters ([72]: pp. 57-79). The cave in question was excavated by the Mexican archaeologist Ángel García Cook during two seasons, carried out in 1969-1970 (Figure 7(B)). During the first intervention, three grids were established (S2E1, S3E1, and S4E1) in which the archaeological potential was evaluated ([66]: pp. 26-28). In 1970, the fieldwork included a larger excavation ([74]b: pp. 23-28) in which a series of detailed records were made of the finds, and the stratigraphy of the site was defined (Figure 7(C)).

At Jaywamachay, nineteen strata were identified, labeled A to N. The archaeological excavation showed that the site was inhabited by different occupations, from early hunter-gatherers to agricultural societies ([76]: pp. 188-218). This paper focuses on the earliest twelve layers: H, I, J, J1, J2, J3, K, K1, L, L1, M, and N (Figure 7(D)). The archaeological sequence recovered there spanned the Terminal Pleistocene to the Middle Holocene ([72]: pp. 57-79, figure 3-10). Stratum H consisted of reddish-brown sandy sediment, 5 - 12 cm thick, covering ~23.8 - 27.35 m². Stratum I, light gray to dark brown, covered ~32.4 - 36.8 m² with thickness varying from 5 - 14 cm. Stratum J, light gray, was 12 cm thick, ranging from 7 - 18 cm towards the cave wall. Stratum J1 was 6 - 10 cm thick, covering 7.43 - 8.75 m². J2, brown to dark gray with a thickness of 9 - 22 cm, covered 9.95 m². J3, light gray to brown, with a thin layer of charcoal, was 10 - 15 cm thick, covering 8.3 - 10.05 m². Stratum K, brown sandy in nature, covered ~36.7 m², with a width ranging from 25 - 54 cm. K1, yellowish sandy, covered 18.2 m² with a thickness of 17 - 60 cm. Stratum L, yellowish and difficult to define, covered ~40 m², 50 cm thick, with long fallen rocks. L1 had the same characteristics and dimensions as L. Stratum M was 20 - 118 cm thick, composed of fallen rocks surrounded by yellowish to gray sand. Finally, above the bedrock, Stratum N was archaeologically sterile, composed of gravel and sand deposited by water displacement.

Figure 7.(A) View of the mouth of the Jaywamachay shelter facing the Cachi River (Copyright: Robert S. Peabody Institute of Archaeology, Phillips Academy). (B) Puente site floor plan of excavations: In yellow, a detail of the first trench excavated at the site in 1969. In sky blue, the excavated area during 1970 ([72]: p. 61). (C) Jaywamachay stratigraphic sequence from profiles S4W1 to S4E6 (redrawn by Juan Yataco). (D) Richard MacNeish and Bryan Vaugh collecting pollen samples at Jaywamachay cave from different layers (photo by Bryan Vaugh).

Analysis

The remains studied and recovered from the twelve aforementioned strata comprise a total of 4388 anthropic lithic pieces. Their stratigraphic distribution is as follows: H (n = 1510), I (n = 1035), J (n = 860), J1 (n = 128), J2 (n = 33), J3 (n = 258), K (n = 155), L (n = 177), and M-N (n = 232). Detailed information regarding artifact class and their discrimination by count and strata is provided elsewhere ([136]: p. 32, Table 2). Materials such as basalt, followed by flint and obsidian, were the most frequently selected by prehistoric flakers throughout the early occupational history of the site (strata H to M-N) (Figure 8(A), Figure 8(B), Figure 8(D), Figure 8(E), Figures 8(G)-(Q), Figures 8(U)-(X)). According to our fieldwork, basalt is locally available in the ravines and surroundings of Jaywamachay. Likewise, this raw material is transported by the Cachi River, which also contains boulders of quartzite, sandstone, volcanic tuff, andesite, granodiorite, among others. The sources of this group of rocks are unknown with certainty. However, with respect to obsidian, we know with precision of the existence of natural deposits in Pozzolana, Quispisisa, Vischongo, and Orco Punco, all of these sources located at a distance that approximately ranges between 20 to 85 km in a straight line from Jaywamachay. A sample of obsidian artifacts (n = 31) recovered from different strata of prehistoric sites within the Ayacucho basin was subjected to X-ray fluorescence and neutron activation analysis by [15]. Five specimens within this sample originated from Jaywamachay, specifically from layers N-M, K, J2, I, and H. Their analysis indicated that the geological source of this obsidian is Quispisisa, located 85.4 km southeast of Jaywamachay ([13]; [15]: p. 219, table 12; [14]; [84]; [40]).

The analysis of the shaped lithic artifacts allowed for the identification of two distinct lithic assemblages characterized by different techno-morphological attributes. Based on the similarities of the tools and their association with consistent calibrated dates, we interpret the archaeological remains from strata H to J as having been deposited by Early Holocene hunter-gatherers between ~≥10.1 and 9.0 kya. These strata yielded biconvex bifacial artifacts exhibiting foliaceous and rhomboidal forms with well-executed finishes achieved through pressure flaking and occasional soft percussion (Figures 8(A)-(L)). There are fractured (Figure 8(A), Figure 8(C), Figure 8(G), Figure 8(I)) and complete specimens that were highly resharpened (Figure 8(B), Figures 8(D)-(F), Figure 8(H), Figures 8(J)-(L)). Due to the characteristics of the flake scars, other bifacial pieces might have been flaked using direct hard hammer percussion techniques. Also, the presence of cortex in some specimens suggests that they are from early stages of bifacial reduction. In addition, there is a significant number of debitage (n = 3010) indicating different stages of bifacial and unifacial reduction from roughed out blanks to the finished products ([136]: tables 2 and 4). In these layers, both the morpho-technology of bifacial points (n = 53) and a large amount of flaking debris suggest the repair and modification of weapons used for hunting; additionally, with the making of unifacial tools (n = 296). These specimens are related to the documented unifacial artifacts; for example, a uniface on a pressure-retouched basalt flake (Figure 8(V)), an obsidian perforator (Figure 8(U)), and scrapers made of flint and quartz (Figures 8(R)-(S)). Basalt in these strata was the most recurrent material (n = 2153), followed by silicified and sharp raw materials such as flint (n = 392), obsidian (n = 310), quartz (n = 248), volcanic tuff (n = 113), and jasper (n = 88), among the favorites. Added to these lithic findings are faunal remains with a total of 139 pieces, presenting in some cases obvious traces of modification; some have been reported as “conical bone awl,” “abrasion modified bones,” “bone fragment,” “tubular bone beads,” and “sawed phalange” (Figures 9(A)-(C), Figures 9(G)-(K); [75]: pp. 314, 317, 319, fig. 8-7, 8-13, 8-16).

Figure 8.Projectile points recovered from the strata Hin Jaywamachay: (A)-(F); I: (G) (H); J: (I)-(L); J2: (M) (N); J3: (O) and K: (P) (Q). Unifacial artifacts from strata H: Scraper; I: Perforator (U); J: Unifacial tools (S), (V); J3: Scraper (T); K: Knife (W); and M-N: flake with marginal retouch (X).

The next temporal moment defined by the radiocarbon dating and the character of the remains consists of the findings from J1 to J3. They correspond to hunter-gatherers who lived during the Pleistocene/Holocene transition between ~≥12.6 - 10.2 kya. At least in strata J2 and J3, three fishtail or Fell points of typical shape made of obsidian were documented. Two of them were fractured in their middle portion (Figure 8(M), Figure 8(O)), and there is one almost complete piece that is missing only the meso-basal portion of the peduncle stem (Figure 8(N)). These were shaped by pressure with irregular parallel retouches on a blade whose edges have a convex form. Although there are three specimens, they are in fact chronological markers that indicate human presence in the Pleistocene/Holocene transition, a phenomenon supported by radiocarbon dating ([135]).

The flaking debitage constitutes a numerically significant component in these strata (n = 376), complementing the recorded manufacturing processes of unifacial and bifacial artifacts. Based on their dimensions and weights, these lithic remains appear to be the products of manufacturing tools generally composed of retouched flakes (n = 10), scrapers (n = 4), and a well-made uniface (n = 1). Additionally, a series of geofacts and miscellaneous objects, including manuports, pebbles, and tablets (n = 23), suggests their transport from the Cachi River bed. The predominant raw material utilized was locally sourced basalt, followed by obsidian, quartz, and flint of undetermined origin. Among the 21 animal bones recovered between strata J1 and J2, stratum J2 yielded three well-crafted tools tentatively identified by MacNeish based on morphological similarities as a “long bone flesher,” a “weaving sword fragment,” and a “cylindrical bone pin” (Figures 9(D)-(F); [75]: p. 316, figures 8-10, 8-11). The latter measures 5 mm in diameter and 42 mm in length, with a cylindrical cross-section and a partially broken tip (Figure 9(F)). The possible flesher is a fragmented diaphysis (89 mm long, 20 mm wide, and 6 mm thick), exhibiting a flattened broken tip with several striae, potentially from manufacturing (Figure 9(D)). The potential weaving sword fragment measures 73 mm in length, 14 mm in width, and 5 mm in thickness (Figure 9(E)). We consider a necessary future revision of these identifications.

A significant number of projectile points (n = 58) have been identified from levels H to K (Figures 8(A)-(Q)). Points from strata H and I are rhomboidal to lanceolate, shaped by soft direct percussion and finished by pressure flaking (Figures 8(A)-(H)). The symmetry of some specimens indicates well-configured pieces, and their shapes, sizes, and weights suggest reshaping and reworking, reflecting careful material economy (Figures 8(C)-(E), Figure 8(H)). As observed at the Puente site ([138]), the retouches show a change in the original flaking pattern, forming rounded or concave edges. This type of repair typically occurs when the piece remains hafted ([16]; [94]).

In the lower strata K to M-N, small unclassified bone fragments have been registered (n = 14), in association with a significant amount of debitage (n = 550), along with unifacial (n = 11), core (n = 1), and bifacial (n = 2) artifacts. These strata lack radiocarbon dates. Based on the shape of the projectile points, we speculate these are from a later period. Their presence suggests potential stratigraphic alterations and material mixing not thoroughly documented. While it is possible that these artifacts represent pre-Fell occupation, we are skeptical. Considering findings from other rock shelters in the region ([135]), it is crucial to conduct specialized archaeological, geo-archaeological, and taphonomic investigations to understand the complex burial processes and site formation.

Figure 9.Bone objects from strata Hat Jaywamachay: Conical bone awls (A), abrasion-modified bones (B) (C), sawed phalanges (K); H-I: tubular bone beads (H)-(J); J: bone fragment (G); J2: long bone fleshers (D), weaving sword fragment (E), cylindrical bone pins (F) ([75]: pp. 316-319).

Flea Cave or Pikimachay is located at 2,925 masl on the eastern slope of Marcahuilca Hill (13˚02'18.93''S. Lat., 74˚13'41.27''W. Long.), a volcanic cone ~2 kilometers northwest of Paccaicasa town. Geologically, it is located in the Molinoyoc formation, consisting of a sequence of dark lavas arising from several volcanic cones, among which five stand out, made up of lava, slag, and ash spills reaching altitudes of approximately 3400 meters above sea level ([40]). In the Paccaicasa surroundings, there is evidence of whitish breccias and tuffs, and colored lava streams ranging from gray to dark gray, with plagioclase and lapilli strata.

The cave measures 25 m long by 55 m wide, and 10 m in height at the entrance (Figure 10(A)). For excavation purposes, the floor was divided into three sectors called the north, central, and south “rooms” ([71]: p. 10). From the cave’s mouth and the drip line, they are located from right to left respectively, around and behind the large blocks mostly found in the north-central portion of the entrance, and partially in the southern portion of the south sector (Figure 10(A), Figure 10(B)). In these “rooms”, three excavation sectors named as North, Central, and South “trenches” were independently excavated, with different notation in record and stratigraphy ([67]; [72]: pp. 19-56; [76]: pp. 133-170). During the first field season between June and September 1969, the team excavated the central and northern sectors. The main excavation was done in the southern portion during the second field season in 1970 (Figure 10(B)). The grids were oriented along the north-south and east-west axes, and labeled according to parallel lines of stakes; units south of this 0 axis were called E1, then E2, etc.; while those 1 m south were S1, S2. Thus, all were crossed by axis lines and had a double number; for example, S14E10.

Figure 10.(A) R. MacNeish and a visitor at Pikimachay cave. Observe the large rockfalls located at the entrance of the central room (photo by Bryan Vaugh). (B) Floor plan of the site and locations of the excavated sectors: in yellow color the excavated grids in 1969 and in sky-blue color the 1970 field-seasons. (C) Stratigraphic sequence of Pikimachay cave from S12E9 to S23E9 and S23E5 to S12E5 ([72]: pp. 46-47). (D) Bryan Vaugh collecting pollen samples at Pikimachay cave from layers h to k (photo courtesy of Bryan Vaugh).

The remains discussed here come from the south room, so here we describe only the strata from this area. There, the sedimentary deposit showed sixteen layers identified with the letters “a” to “k” (Figure 10(C)). Some remarkable features are in the sequence. The blocks fallen in the collapse of the cave’s ceiling constituted a clear-cut layer in the stratigraphy ([72]: p. 49). Strata “g,” about 1.5 m in thickness, is composed of rodent-deposited plant remains and blocks of varying sizes. The blocks are mostly concentrated in the north-central region, and partly in the southern sector (Figures 10(A)-(C)). Because they overlie an occupation level with projectile points dated at about 10,000 - 9000 uncalibrated years (~10-9 kya, hereafter) ([67]: pp. 29-40; [72]: pp. 51-54), these rock-falls were possibly caused by a catastrophic episode that happened during the terminal Pleistocene/Early Holocene, and covered the seven earliest strata ([66]: pp. 17-23). The stratigraphy overlying this debris is confusing and showed disturbances and intrusions due to modern human action, such as looter holes, the construction of corrals, and animal activity ([67]: pp. 4-8). Due to its thickness, some significant unconformities may have occurred, mainly above the blocks ([140]). However, the underlying strata show a moderately uniform horizontal deposition forming a deposit ≥1.5 m thick. We will describe these strata due to the goal of our investigation (Figure 10(C)).

Layer h, 20 cm thick, formed by dust and soft reddish-brown sediment, is the last deposit before the cave’s ceiling collapses. It occupied a small triangular surface of 21.75 m², approximately 6 × 6 m, at the north end of the excavation. The most extensive stratum below the rock fall was h, formed by slightly compact reddish-orange sediment. Its thickness varies from 5 to 10 cm along the cave wall to greater than 30 cm near the cave’s mouth and extends over 119.13 m². Below is the h1 stratum, a highly compact yellowish deposit with a maximum thickness of ~40 - 50 cm, and an average ranging from 25 to 35 cm. It covers a surface of 122 m², and only 104 m² was excavated. Covering a surface between 50 to 60 m², i was a dark brown layer reaching a maximum of ~30 cm in thickness. Measuring ~7 - 8 meters in an east-west direction, i1 was a compacted reddish-brown stratum of ~30 cm maximum thickness. The excavation consisted of an area of 20.5 m², and the unexcavated surface was 3.13 m². Extending between 8 to 14 m from east to west, stratum j is dark reddish-gray sediment which reached a maximum thickness of 40 cm. It covered an approximate area of 50 to 65 m², of which only 33.42 m² was exposed. Finally, overlaying the bedrock, k is a brownish-gray level with a maximum thickness of 30 cm. It covered a surface of 10 by 4 meters long and wide, with an excavated surface of 27.71 m².

In summary, two features are crucial in the lower levels of the Pikimachay sedimentary deposit. They are the collapse of the cave’s roof, which in several places sealed the oldest strata that showed a reasonably horizontal and uniform deposition, only disturbed by falling roof blocks in some places of h and h ([67]: pp. 33-41). The rockfalls from the cave walls and ceiling occurred in strata related to tabular volcanic flows and weak areas associated with tectonics and seismic activity ([72]). Another notable feature is that layers h to k (Figure 10(C), Figure 10(D)) show a highly compacted structure, almost lithified, and practically reaching a cemented stage in the sedimentary rock formation process ([7]; [130]; Yataco & Nami, several personal observations). As the layers thickened, this part of the stratigraphy became harder ([67]: p. 18). For that reason, chisels were used for excavation (Figure 10(D)), and their signatures are still visible in the remaining sections. These sorts of hard layers seem to be present in other sites, such as the Puente rockshelter. There, to excavate them, chisels were also used ([66], fig. 37; [138], fig. 5 a-d). These kinds of highly compacted strata might have acted as a matrix sealing the embedded artifacts.

Analysis

The re-study and analysis of the archaeological materials from layers h, h1, and i1 at this site yielded a total of 67 anthropogenic artifacts. Because the field notebooks at the RSPIA help identify artifacts curated at the MAA-UNMSM ([140]), we added fifteen new pieces to the previously reported sample (n = 52, [139]: pp. 257-265). The sample may be classified as follows: tools (n = 33), bifaces (n = 2), lithic waste (n = 21), cores (n = 8), as well as manuports and ecofacts (n = 3). The total and detailed data regarding each specimen’s location in the stratigraphic sequence, catalog numbers, excavation squares, and their individual figures are given in published and unpublished literature ([139]; [140]). In making the flaked artifacts, sedimentary, metamorphic, and igneous rocks in various colors are used. The most used raw materials in the h and h1 layers were volcanic rocks, mainly tuff (n = 25), basalt (n = 5), minerals like quartz (n = 13), and chert (n = 13). Three waste flakes were detected in layer h, made of basalt with a black coloration (Figure 12(E)), pebble debris (Figure 12(M)), a chopper that exhibits a strongly rounded and ground edge (Figure 11(K)), among others. Remarkable are nine shaped tools, among which are two made from flake-blanks of volcanic rock (Figure 12(G), Figure 12(M)). Two multipurpose tools ([49]; [99]) were probably used as knives or side scrapers (Figure 11(B), Figure 11(L)); additionally, there is a denticulate tool (Figure 12(K)). Five cores were made from chert and dacitic metavolcanic material (Figure 11(O); Figure 12(A), Figure 12(H)); flake fragments, a knife, and shatter (Figure 11(S)) are made of chert. All the described specimens seem exhausted, and the flake-scars’ concavities and flake shapes indicate that they were flaked by direct hard percussion. We also examined seven tools, including a scraper that stands out by its shape (Figure 11(M)), two modified flakes (Figure 11(E), Figure 11(F’)), and three denticulate tools (Figure 11(D), Figure 11(N), Figure 11(I)); finally, a perforator (Figure 11(A)). Remarkable is an end-scraper manufactured on a small tertiary angular flake of smoky black obsidian (Figure 11(H)). This example is significant because it shows the early presence of obsidian use in Ayacucho. What is more, another scraper on volcanic tuff is from the same context (Figure 11(J)). Two partially flaked bifaces (Figure 11(C), Figure 11(G)) were flaked on a moderately yellow-green andesitic volcanic tuff rock with microfractures filled with milky quartz. Due to the raw material flaws and the fracture patterns, both were possibly rejected during the reduction process ([18]; [88]; among others).

Most debitage consists of secondary and tertiary flakes of different materials (n = 14). Two are primary flakes on basalt (Figure 11(P); Figure 12(C)), and four pieces of shatter on volcanic tuff (Figure 11(Q) and Figure 12(B)). In at least six of these pieces, the cortex suggests that they were removed from pebbles and result from the initial stages of reduction chipped with hard percussion flaking (Figure 11(Q), Figure 11(T) and Figure 12(E), Figure 12(G),Figure 12(I), Figure 12(M)), and one, due to its morphology, was obtained using soft percussion (Figure 11(R)) ([18]; [98]; [134]). This waste may indicate that, on certain occasions, the flaking of volcanic tuff, flint-like material, diabase, and basalt may have been carried out inside the cave, as suggested by several archaeological and actualistic investigations ([35]; [18]; [131]). It is important to note that a substantial portion of the sample is waste (44%), which includes cores (11%) and debitage (33%). The most used materials were basalt, diabase, volcanic tuff, and granodiorite, followed by quartzite; also, sandstone, quartz, jasper, flint-like materials, and obsidian were used to a lesser extent (Figure 11, Figure 12). Local sources for lithic materials are possible; a small primary outcrop of silicified material was found near Molinoyoq volcano, ~300 meters from Pikimachay. However, regional landscape changes over millennia due to agriculture may have obscured some resources. Our analysis showed a dominant use of volcanic rocks, mainly silicified tuff (n = 21), with less basalt (n = 3) and diabase (n = 1). These rocks are still found in secondary deposits near the cave or along the Cachi River, given the widespread volcanic materials from at least three nearby volcanoes ([138]). Due to past controversies and the lack of detailed review ([31]; [58]; [123]), the precise origin, descriptions, quantities, and context of these finds are detailed in [140].

Figure 11. Stone tools from layers h (A)-(T); h1 ((U)-(Z), (A’)-(J’)) and j (K’) in Pikimachay.

Five pieces of volcanic chipping waste were identified (Figure 11(U), Figure 11(V), Figure 11(C’), Figure 11(E’), Figure 11(G’)). Shaped artifacts include tools (n = 8) and cores (n = 2), mostly in Figure 11(A), Figure 11(H). Two scrapers (Figure 11(X), Figure 11(H’)) of bluish flint-like material and white quartz exhibit short, irregular parallel retouches with an abrupt angle and a continuous distribution on their distal or perimeter edges. Among shaped specimens on secondary flakes are three denticulate tools on flint (Figure 11(Y)), marbled quartz (Figure 11(J’)), and quartzite (Figure 11(I)), with continuous abrupt to semi-abrupt retouch, sometimes perimetric. Two of these were previously noted by [67]. A likely exhausted trapezoidal core of marbled volcanic tuff with ~50% cortex and facets suggests selection of an angular nodule (Figure 11(A’)). MacNeish’s files also identified three waste flakes from layer h1 with possible soot stains, soot, or fire exposure, one cracked (Figure 11(V), Figure 11(B’)) ([115]).

Figure 12.Lithic artifacts from layer h(A)-(M) at Pikimachay.

The artifacts described above allow for some remarks regarding their reduction sequence. The cortex of some nodules remains on the dorsal face, suggesting that they were detached from pebbles (Figure 11(A’)), or even nodules with angular surfaces (Figure 11(E’)). Because of the material’s workability, they may have been detached by hard hammer percussion flaking ([18], 2016; [88], 2000, 2015), among others. Also, several large flake-blanks on the ventral face display flat or diffuse force cones (Figure 11(U), Figure 11(Y), Figure 11(C’), Figure 11(H’)). Flaking experiments on similar South American materials showed that this attribute results from using hard hammerstones ([97]). Due to the features observed on the dorsal faces, percussion was randomly applied to different kinds of cores, including the bifacial and amorphous cores observed in the collection (Figure 11(A’), Figure 11(E’)). The percussion was applied to unmodified or previously flaked surfaces, which can be observed in the flakes as natural, plain, and dihedral butts of striking platforms (Figure 11(W), Figure 11(D’)). It is highly probable that after the blank was obtained, the final shaping was performed by simply retouching its edges using the same technique, but with another variant and/or holding position, and using hard, soft, or semi-soft hammer-stones (e.g., [101]; [26]). In some circumstances (Figure 11(X), Figure 11(Y), Figure 11(D’),Figures 11(H’)-(J’)), the tools’ edges were possibly shaped by pressure flaking or by percussion with a soft implement, probably of an organic nature, with high-density osseous tissue, like deer antler ([102]). The retouch forms vary from short parallel (Figure 11(X), Figure 11(Y), Figure 11(C’)) to scaliform (Figure 11(B’), Figure 11(F’), Figure 11(J’)), and when the dorsal and ventral faces are visible, most retouches are direct (Figure 11(W), Figure 11(X), Figure 11(Y), Figure 11(B’), Figure 11(J’)), and inverse in a few cases (Figure 11(U), Figure 11(C’), Figure 11(H’)).

MacNeish and colleagues ([67]: pp. 21-41; [76]: pp. 141-143) also reported from layer i supposed activity areas containing bones, burned sectors, and lithic artifacts. To determine their possible human modification, each piece was reviewed with special care and detail (e.g., Figure 13(D), Figure 13(F), and Figure 13(G)); their edges were carefully examined for striking platforms and impact points to assess their true human-made nature. Although it was difficult to determine the cause of the fractures, we concluded that the rocks fell down the cave walls and roof, and they are without intentional human modification. Some have natural fractures on the edges, thus constituting nature artefacts or geofacts ([82]; [114]). We consider them to be rocks that exhibit a series of apparently morpho-technological features whose origin is due to geological processes ([34]). During our case study, we observed chunks and flake-like pieces detached from the cave outcrop and chemically altered by natural agents, sometimes showing continuous, non-continuous, or random flake scars. Thus, no evidence of human activity can be seen in this stratum, and hence, we reject them as anthropogenic. One piece exhumed from layer i1 is curated at the MAA-UNMSM and described as a core on quartzite with angular surfaces (Figure 11(K’)); it is an artifact showing flake detachments from hard hammer-stones. As we previously discussed, this core may come from the upper levels ([140]: p. 315; [139]: p. 258), and there is no human activity. About layers j and k ([67]: pp. 21-25. fig. 21; [75]: fig. 3-1, 5-3). MacNeish reports a possible stone tool as a “tufa flake chopper,” “large denticulate,” and “a tufa slab spokeshave” (Figures 13(A)-(C) and Figure 13(E)). After reviewing these pieces, we concluded that they were natural rocks.

Figure 13.Chunks and geofacts from south room layersk ((A), (B)); j ((C), (E)); i ((D), (F), (G)); h1 ((H), (I), (J)); h ((K), (L)); g ((M), (N)); e (O); d (P); b (R); a1 (Q).

Remarkably, MacNeish also unearthed similar apparent pseudo-artifacts in the same south section across late Pleistocene, Middle, and Late Holocene contexts (layers h1, h, g, e, d, b, and a1; Figures 13(H)-(R)). Our meticulous examination of the cave and its debris-strewn surroundings, searching for pseudo-artifacts akin to those in Pikimachay’s lower levels, yielded several pieces published as “tufa slab spokeshaves” (Figure 13(H), Figure 13(I), Figure 13(K)), “large denticulate” (Figure 13(J)), “pebble side scraper” (Figure 13(L)), and other undetermined items from later levels (Figures 13(M)-(R)) ([67]: pp. 21-25; [75]: fig. 5-1, 5-3). As Figure 13 illustrates, these exhibit dimensional and shape similarities to those from the lower layers. Furthermore, our recent visit to the cave resulted in the recovery of comparable items among the fallen debris. Based on these observations, we strongly reiterate our interpretation that certain stones from layers h, h1 (Figures 13(H)-(L)) and others from i, i1, j, and k, classified by MacNeish as “artifacts” (Figures 13(A)-(G)), are of natural origin and not humanly modified.