五峰國家(jia)(jia)地(di)(di)質公園位于湖北(bei)五峰土(tu)家(jia)(jia)族自治縣(xian),地(di)(di)處武陵(ling)山(shan)脈北(bei)延的中(zhong)山(shan)區,園內(nei)擁(yong)有(you)完(wan)(wan)整的巖溶體系(xi)、典型的構造(zao)遺跡(ji)和地(di)(di)質層型剖面等重(zhong)要地(di)(di)質遺跡(ji),面積為194.75平方千米,擁(yong)有(you)重(zhong)要地(di)(di)質遺跡(ji)點77處,其(qi)中(zhong)國家(jia)(jia)級地(di)(di)質遺跡(ji)點3處。后河園區以(yi)國內(nei)罕見的珍(zhen)(zhen)稀孑遺動(dong)植(zhi)(zhi)物群(qun)落(luo)、峽(xia)谷絕(jue)壁景觀為特(te)色,有(you)中(zhong)緯度地(di)(di)帶保存最完(wan)(wan)好的原始森林生態(tai)系(xi)統,尤以(yi)大片保存完(wan)(wan)好的水絲梨、珙桐、紅豆杉等古植(zhi)(zhi)物群(qun)落(luo)為稀世珍(zhen)(zhen)寶,是中(zhong)國重(zhong)要的“植(zhi)(zhi)物基(ji)因庫”。
遺跡類型
湖北五峰地(di)質(zhi)公園內的(de)(de)(de)地(di)質(zhi)遺跡景(jing)(jing)觀(guan)類(lei)(lei)型(xing)主要包括(kuo)以(yi)五峰組剖面(mian)為主的(de)(de)(de)典型(xing)地(di)質(zhi)剖面(mian)景(jing)(jing)觀(guan);以(yi)巖溶地(di)貌(mao)(mao)(mao)、構(gou)造地(di)貌(mao)(mao)(mao)為主的(de)(de)(de)地(di)質(zhi)地(di)貌(mao)(mao)(mao)景(jing)(jing)觀(guan);以(yi)腕足類(lei)(lei)、筆石類(lei)(lei)、三葉(xie)蟲類(lei)(lei),以(yi)及豐(feng)富的(de)(de)(de)沉(chen)積構(gou)造(古(gu)生物(wu)活動(dong)(dong)遺跡)、孑遺動(dong)(dong)植(zhi)物(wu)活化石等為主的(de)(de)(de)古(gu)生物(wu)景(jing)(jing)觀(guan)。其中(zhong)以(yi)地(di)質(zhi)地(di)貌(mao)(mao)(mao)中(zhong)巖溶地(di)貌(mao)(mao)(mao)景(jing)(jing)觀(guan)最具特色。
巖溶地貌景觀
五峰(feng)園區內碳(tan)酸鹽巖(yan)(yan)出露(lu)面積達70%以上。地面巖(yan)(yan)溶(rong)(rong)(rong)廣泛發育,巖(yan)(yan)洞、巖(yan)(yan)槽(cao)、巖(yan)(yan)溶(rong)(rong)(rong)洼地、巖(yan)(yan)溶(rong)(rong)(rong)槽(cao)谷及構造(zao)侵蝕溶(rong)(rong)(rong)蝕巖(yan)(yan)谷廣布,形(xing)態多樣,地下(xia)巖(yan)(yan)溶(rong)(rong)(rong)(層間(jian)溶(rong)(rong)(rong)隙(xi)、落水(shui)洞及水(shui)平溶(rong)(rong)(rong)洞)已經相互溝(gou)通(tong),形(xing)成(cheng)了(le)地下(xia)巖(yan)(yan)溶(rong)(rong)(rong)管(guan)道(dao)網絡,并造(zao)成(cheng)地表水(shui)斷流、干枯(ku),構成(cheng)了(le)奇特的(de)巖(yan)(yan)溶(rong)(rong)(rong)化(hua)地貌。
巖溶峽谷——柴埠溪大峽谷
柴埠溪大(da)峽(xia)谷沿長(chang)樂坪背(bei)斜(xie)軸部(bu)(bu)的張性(xing)斷(duan)裂(lie)發(fa)育,這一(yi)部(bu)(bu)位巖(yan)層破碎(sui),是地(di)表水(shui)大(da)量入滲和集中(zhong)產出的區域。在地(di)殼抬(tai)升(sheng)的過程(cheng)中(zhong),水(shui)流不斷(duan)侵蝕(shi)下(xia)切,巖(yan)洞逐步(bu)坍塌,最終形成了柴埠溪“U”型大(da)峽(xia)谷。
峽谷(gu)兩側的(de)(de)地(di)層(ceng)緩緩向(xiang)山內傾斜,巖層(ceng)不(bu)易順坡(po)向(xiang)滑落。在(zai)侵蝕(shi)、溶蝕(shi)和重力等(deng)地(di)質作用下,被剝(bo)蝕(shi)的(de)(de)巖體不(bu)斷崩(beng)落而被河流(liu)帶走,殘留的(de)(de)巖層(ceng)容易形成直立的(de)(de)巖溶石柱。
峽谷周邊的(de)(de)地表水有的(de)(de)匯(hui)聚于(yu)(yu)巖(yan)溶(rong)(rong)槽谷或巖(yan)溶(rong)(rong)漏斗,通過巖(yan)溶(rong)(rong)洞(dong)穴匯(hui)入河(he)道。在河(he)道進一步下(xia)切的(de)(de)過程中,也(ye)加劇了出水口(kou)這(zhe)些匯(hui)水地帶的(de)(de)侵蝕和溶(rong)(rong)蝕作用,從而形成像“壇(tan)子口(kou)”、“大灣口(kou)”、“斷山口(kou)”等等這(zhe)樣的(de)(de)高陡缺口(kou)。正是由于(yu)(yu)這(zhe)一特(te)殊(shu)的(de)(de)地質(zhi)條件(jian),造(zao)就了柴埠溪“幽峽百里(li),奇峰三千”的(de)(de)地貌景觀。
2.溶洞——長生洞
據考察,五峰境(jing)內大小溶(rong)(rong)(rong)洞(dong)(dong)(dong)(dong)有(you)上(shang)千個(ge)(ge),其中(zhong)以長(chang)(chang)生洞(dong)(dong)(dong)(dong)規模最(zui)大。長(chang)(chang)生洞(dong)(dong)(dong)(dong)全(quan)(quan)長(chang)(chang)約4 km(已(yi)開發1 500 m),縱(zong)深300 m,上(shang)下(xia)高差150 m。洞(dong)(dong)(dong)(dong)中(zhong)有(you)洞(dong)(dong)(dong)(dong),樓(lou)上(shang)有(you)樓(lou),景(jing)(jing)中(zhong)有(you)景(jing)(jing),下(xia)有(you)廳堂,上(shang)有(you)長(chang)(chang)廊,蜿蜒(yan)曲折,縱(zong)橫交錯(cuo)。洞(dong)(dong)(dong)(dong)中(zhong)石(shi)(shi)筍、石(shi)(shi)鐘乳和石(shi)(shi)幔等(deng)巖溶(rong)(rong)(rong)景(jing)(jing)觀(guan)十分豐富,斷(duan)臂女(nv)神(shen)維納(na)斯、定(ding)海神(shen)針、雙龍盤柱、金雞報(bao)曉(xiao)、水晶(jing)冰(bing)簾、仙花(hua)仙果、凱旋門、蓮(lian)花(hua)峰等(deng)經(jing)典(dian)迷人景(jing)(jing)致巧(qiao)奪(duo)天(tian)工,令人目不暇(xia)接。長(chang)(chang)生洞(dong)(dong)(dong)(dong)是(shi)一座(zuo)“天(tian)工藝術大寶庫”和“名(ming)不虛(xu)傳的(de)地下(xia)宮殿(dian)”,被譽為“洞(dong)(dong)(dong)(dong)景(jing)(jing)之冠”。已(yi)開發的(de)長(chang)(chang)生洞(dong)(dong)(dong)(dong)發育于(yu)寒武系(xi)的(de)灰巖中(zhong),地下(xia)水順褶皺軸部的(de)張性斷(duan)層溶(rong)(rong)(rong)蝕(shi),被溶(rong)(rong)(rong)蝕(shi)的(de)物質(zhi)沿斷(duan)層通道(dao)排出,洞(dong)(dong)(dong)(dong)體因(yin)坍(tan)塌與溶(rong)(rong)(rong)蝕(shi)而(er)逐漸擴大。整(zheng)個(ge)(ge)溶(rong)(rong)(rong)洞(dong)(dong)(dong)(dong)構成復雜,支洞(dong)(dong)(dong)(dong)繁生,歧路四(si)伏,按溶(rong)(rong)(rong)洞(dong)(dong)(dong)(dong)結構和典(dian)型景(jing)(jing)觀(guan),全(quan)(quan)洞(dong)(dong)(dong)(dong)分為7個(ge)(ge)景(jing)(jing)群,即春(chun)和樓(lou)、仙人坡、靈隱宮、長(chang)(chang)廊、天(tian)臺、凱旋門、冬宮。
3.槽谷與峰叢
灣(wan)譚鎮(zhen)是(shi)鄂西地(di)(di)區典型的(de)巖(yan)溶發育區,在(zai)山(shan)水(shui)的(de)對抗(kang)中(zhong),形成槽谷(gu)(gu)與峰(feng)(feng)叢共生,溶洞(dong)(dong)與暗(an)(an)河相(xiang)連(lian)的(de)景觀畫卷。灣(wan)譚鎮(zhen)發育的(de)眾(zhong)多槽谷(gu)(gu)中(zhong)以(yi)灣(wan)譚槽谷(gu)(gu)規(gui)模最大,谷(gu)(gu)內時而平地(di)(di)拔(ba)起(qi)一(yi)座座巖(yan)溶殘留的(de)“孤峰(feng)(feng)”,地(di)(di)勢低洼處可見(jian)到落水(shui)洞(dong)(dong),豐(feng)水(shui)時節河水(shui)則主要通過落水(shui)洞(dong)(dong)流入暗(an)(an)河。河槽的(de)四(si)周(zhou)是(shi)典型的(de)峰(feng)(feng)叢地(di)(di)貌,一(yi)座座錐(zhui)狀山(shan)峰(feng)(feng),高低不同,錯落有致。
4.溶溝
白鹿(lu)景區是由奧陶系寶塔組的龜(gui)裂(lie)紋灰巖組成(cheng),巖層(ceng)產狀(zhuang)順(shun)坡向緩緩傾斜,水流的長期溶蝕作用形成(cheng)縱向溶溝,與橫向的卸荷裂(lie)隙構成(cheng)網格狀(zhuang),就像一(yi)座沒有頂蓋的迷宮(gong)。有的溶縫(feng)(feng)非常狹窄(zhai),仰頭望(wang)去,天空就像一(yi)條藍(lan)藍(lan)的細線。有的溶縫(feng)(feng)上窄(zhai)下寬,有的溶縫(feng)(feng)頂部相(xiang)連,宛如一(yi)座石壘的地(di)宮(gong)。這里如同(tong)柴埠溪(xi)的縮(suo)影,雖然少了(le)柴埠溪(xi)的雄和險的氣勢,卻更給人以秀和美的感(gan)受。
5.天生橋
天(tian)生橋是地下河與溶洞的(de)頂(ding)部崩(beng)塌(ta)后,殘留的(de)頂(ding)板橫跨(kua)河谷兩岸(an),形似拱橋。五峰(feng)地質公園內的(de)一座天(tian)生橋,寬約(yue)2.5 m,高(gao)約(yue)30 m,橋面平坦,形態(tai)規整(zheng)。
地質剖面景觀
五峰地(di)(di)質(zhi)公園典型(xing)地(di)(di)質(zhi)剖面景觀主要包含有典型(xing)地(di)(di)層剖面和典型(xing)地(di)(di)質(zhi)構造(zao)剖面。
五(wu)峰(feng)組地(di)(di)層(ceng)剖面一直是地(di)(di)層(ceng)古生(sheng)物學界的(de)研究熱點(dian)。著名(ming)的(de)五(wu)峰(feng)頁巖以(yi)及其中富含的(de)筆石化石地(di)(di)層(ceng)對(dui)揭示志留(liu)紀-奧陶紀之交的(de)地(di)(di)球的(de)環(huan)境變(bian)化特征(zheng)具有重要意義(yi)。
自1931年(nian)孫云鑄教授命(ming)名“五峰組”以(yi)來(lai),在地質學界,特別在地層學、古生物學等領域引發了70多(duo)年(nian)的科(ke)(ke)學探討,探討的核(he)心科(ke)(ke)學問題(ti)就(jiu)是五峰頁巖(yan)段的沉(chen)積(ji)環境,因(yin)為(wei)它是揭示中國南方地區古生代早中期過渡(du)期環境變遷(qian)、演(yan)化特征的非(fei)常重要的一把(ba)鑰匙(chi)。
紅溢坪向斜(xie)規模宏大,行跡清晰,將園區的白溢寨與紅溢坪形(xing)成一(yi)個(ge)東(dong)西相連的整體,神似“鬼斧神工之(zhi)作”。向斜(xie)核(he)部為三疊(die)紀(ji)薄層(ceng)灰(hui)巖,兩翼為二疊(die)紀(ji)的厚層(ceng)灰(hui)巖。由于(yu)河(he)流(liu)和(he)幾組大型(xing)裂(lie)隙垂直于(yu)褶皺發育(yu),長期的溶蝕(shi)和(he)侵蝕(shi),形(xing)成的平(ping)臺和(he)絕壁更是(shi)獨具特色。
古生物景觀
五峰地(di)(di)質公園(yuan)內古(gu)生物(wu)景(jing)觀主要包括豐富的(de)古(gu)生物(wu)化(hua)石(shi)(shi)(shi)和沉積構(gou)(gou)造(zao)。園(yuan)區(qu)內不(bu)同(tong)時代的(de)地(di)(di)層(ceng)中(zhong)(zhong)都保存(cun)了眾多類(lei)(lei)型的(de)古(gu)生物(wu)化(hua)石(shi)(shi)(shi)和沉積構(gou)(gou)造(zao)。古(gu)生物(wu)化(hua)石(shi)(shi)(shi)主要有筆(bi)石(shi)(shi)(shi)、牙形石(shi)(shi)(shi)、三(san)葉蟲、腕足類(lei)(lei)、頭(tou)足類(lei)(lei)等(deng)。筆(bi)石(shi)(shi)(shi)是(shi)生存(cun)于(yu)古(gu)生代的(de)一(yi)種已經絕滅(mie)的(de)海(hai)生浮游動(dong)物(wu),由(you)于(yu)它的(de)化(hua)石(shi)(shi)(shi)很像(xiang)保存(cun)在巖(yan)石(shi)(shi)(shi)層(ceng)面上(shang)的(de)筆(bi)跡(ji)而得名。筆(bi)石(shi)(shi)(shi)動(dong)物(wu)群進化(hua)快,遷移廣,盛衰期分(fen)明,成為古(gu)生物(wu)學(xue)中(zhong)(zhong)一(yi)個重(zhong)要門類(lei)(lei),是(shi)鑒別古(gu)生代早、中(zhong)(zhong)期,特別是(shi)奧陶紀(ji)、志留(liu)紀(ji)及早泥盆世地(di)(di)層(ceng)的(de)十分(fen)重(zhong)要的(de)標準(zhun)化(hua)石(shi)(shi)(shi)。
暑天冰穴
在(zai)(zai)白溢寨主(zhu)峰(feng)(黑峰(feng)尖(jian))的(de)(de)絕壁腳下,大(da)量崩(beng)塌的(de)(de)石(shi)塊堆(dui)積在(zai)(zai)沿裂隙(xi)發育的(de)(de)巖溶(rong)通(tong)道之上(shang),石(shi)灰巖石(shi)塊之間的(de)(de)空隙(xi)與巖溶(rong)通(tong)道相(xiang)(xiang)連,內外氣(qi)流在(zai)(zai)此相(xiang)(xiang)聚,由于(yu)溫(wen)差巨大(da),形(xing)成“盛(sheng)夏結冰,寒冬暖巢”的(de)(de)“暑天冰穴”奇觀。
夷平面
此外,園(yuan)區(qu)夷平面發育,他們既是(shi)一道道登高覽勝的(de)風(feng)景線,也是(shi)研究新構造運動間歇式的(de)拱曲(qu)上升和地質環境變遷的(de)證據。